/Engine/Plugins/Experimental/Mutable/Source/CustomizableObject/Public/MuCO/UnrealMutableModelDiskStreamer.h
Start a data request operation.
a previously unused identifier, now used for this operation, that can be used in calls to the other methods of this interface. If the return value is negative it indicates an unrecoverable error.
virtual [OPERATION_ID](API\Plugins\MutableRuntime\MuR\ModelReader\OPERATION_ID) BeginReadBlock ( const [mu::Model](API\Plugins\MutableRuntime\MuR\Model) *, uint64 key0, void * pBuffer, uint64 size, [TFunction](API\Runtime\Core\GenericPlatform\TFunction)< void(boolbSuccess)> * CompletionCallback )